GPUs and CPUs have a significantly different architecture and there is still a ton of lower hanging fruit to improve performance.

What “performance” even means between the two things aren’t even the same thing. CPUs provide a robust instruction set with many features for general purpose computing. GPUs handle a specific subset of problem, do so with a smaller and more specialized instruction set, and are architected for a specific purpose.

Consider that GPUs are much newer than CPUs. The work GPUs do used to be done by the CPU? Why bother inventing a dedicated GPU? Why not just keep adding cores to the CPU? Because they handle a fundamentally different task and are specialized for it.

For several reasons (but technology maturity is certainly one) it doesn’t make a ton of sense to make an apples to apples comparison between CPUs and GPUs. And the idea that CPU single threaded performance is being artificially restricted by an international government effort in the name of defense security is a much more complicated answer than required to explain the difference.